333 
Measurement of three Degrees of the Meridian. 
These values are, as appears, perfectly in conformity with 
the theory, and with the results of other measures that have 
been taken in different parts of the northern hemisphere ; but, 
in order to place that agreement in a more distinct point of 
view, I shall show how nearly these estimates agree with the 
elliptic hypothesis, by comparing them with those measures 
of a degree, on which we can place the greatest reliance for 
exactness. 
Now, if we compare the results of these calculations with 
those deduced by Lieut. Col. Mudge from his observations, we 
shall see the probable source of those errors, which it appears 
to me have led him to false conclusions. It has already been 
observed, that the station at Arbury Hill divides the whole 
arc into two parts nearly equal, and that it is also nearly in 
the meridian of the two extremities at Bunnose and Clifton. 
It was, in all probability, this circumstance which determined 
the author to observe the latitude of Arbury Hill, as he would 
then have two partial arcs independent of the whole and of 
each other. 
For determining the angular extent of these arcs, Lieut. Col. 
Mudge observed the zenith distances of several stars on the 
meridian above the pole, by means of a large zenith sector 
constructed by Ramsden, with the same pains that he had 
bestowed upon the theodolite. Lieut. Col. Mudge paid all 
possible attention, and took all such precautions as might na- 
turally be expected from an observer of his experience and 
address. Nevertheless the results of his observations made 
on different stars, differ no less than 4 seconds from each 
other. But, by taking a mean of all, the dimensions of the 
three arcs reduced to the centre at each station are as follows. 
MDCCCXII. X X 
